the align property (of @text)

[Mouvedia]

We currently have this

@text {
align: (left) | right | center | justify | <number>; //for horizontal alignment
}

I am proposing of adding vertical alignment too:

@text {
align: (left) | right | center | justify | <number> , (baseline) | sup | sub | top | bottom | middle | <number>;
}

But there's a caveat: setting only the horizontal one will require a value for the vertical one:

@text {
align: left, sup;
}

In these cases we can use alignX/Y:

@text {
alignY: sup;
}

[Mouvedia]

Closing this as a duplicate of #57.